AWS Certified CloudOps Engineer Associate SOA-C03 Practice Question

c5n.9xlarge instances are drop-in replacements for c5.9xlarge but include the "n" network-optimized variant, increasing available bandwidth from 10 Gbps to up to 50 Gbps on Nitro without any additional configuration. Switching the instance type in the launch template is a minimal, low-risk change that immediately satisfies the >20 Gbps requirement.

Cluster placement groups cannot span multiple Availability Zones, so re-architecting the Auto Scaling group to use one would require sacrificing AZ resilience and still would not raise the hard network cap of the c5 instances. Enabling jumbo frames improves efficiency but cannot raise the instance's maximum throughput limit. Elastic Fabric Adapter is designed for HPC and requires a cluster placement group in a single AZ; it does not increase bandwidth across AZs for general TCP traffic and adds operational complexity.